International conference at Atlantic Beach, N.C. will focus on 'strange' quarks

The 7th International Conference on Strangeness in Quark Matter, sponsored by Duke University, Brookhaven National Laboratory and MIT, will be held at the Sheraton Atlantic Beach Oceanfront Hotel from March 12-17, 2003.

"Strange" is the name of the type of one of six kinds of fundamental sub-nuclear particles known as quarks. The two lightest types -- or "flavors" as they are known by physicists -- are "up" and "down" quarks. These two flavors make up all the protons and neutrons in atoms and are hence the fundamental constituents of all familiar matter.

Strange quarks "occupy a special niche" among the other four quark types, said Berndt Mueller, a Duke physics professor and dean of natural sciences who is a leading theoretician on the role that strange quarks might have played in the first microseconds of the early universe.

"While they are quite a bit heavier than the quarks that make up protons and neutrons, they are light enough to be produced in processes that occur in our universe almost every day," Mueller said.

"There are indications that some neutron stars are not actually made up predominantly of neutrons but instead of quarks, a considerable fraction of which would be strange quarks," added Steffen A. Bass, a Duke assistant professor of physics and another nuclear theoretician who also works at Brookhaven. Neutron stars are the corpses of very large stars whose thermonuclear fires have exhausted and that have collapsed down to superdense objects that are among the most exotic denizens of the universe.

Just microseconds after the Big Bang, the stupendous explosion that began the universe, conditions are believed to have been too hot for today's protons and neutrons to exist. Matter instead might have existed as a highly energized gas called a quark-gluon plasma. "There are a number of calculations which would leave us to believe that strangeness was far more abundant then," Bass added.

At Brookhaven's Relativistic Heavy Ion Collider, electrically charged gold atoms are being slammed together at tremendous energies in an attempt to recreate that initial quark-gluon plasma, and the production of strange quarks is measured.

Meanwhile, scientists such as Mueller and Bass also ponder whether a hypothesized form of matter called a "strangelet" that includes strange quarks might be a constituent of heavy and invisible dark matter. The mysterious dark matter, which is not part of the visible matter found in stars, is thought to be a major constituent of the universe, so prevalent as to affect the universe's very structure.

Some suspect such loose strange matter might also occasionally pass through the Earth, causing earthquakes that sometimes cannot be tied to a specific earthquake fault, Mueller said.

According to Mueller and Bass, universities in North Carolina's Research Triangle, including Duke, N.C. State and the University of North Carolina at Chapel Hill, are collectively one of the largest centers for theoretical nuclear physics in the United States and at the forefront of quark-gluon-plasma research.